Watkins, the No. 4 pick in this year's draft, was holding his left side after an incomplete pass from quarterback EJ Manuel on Buffalo's first series at Heinz Field.

The former Clemson star has looked the part of the No. 4 pick on the practice field. But he didn't catch a pass in the Bills preseason opener in the Hall of Fame Game against the New York Giants (targeted three times). In the Bills' second preseason game against the Carolina Panthers, Watkins caught three passes for 21 yards.

In three seasons at Clemson, Watkins caught 240 passes for 3,391 yards and 27 touchdowns. On those catches, 48 were for 20 yards or more.